1. Field of the Invention
The present invention relates to technologies for measuring the properties of materials such as biological tissues or engineering materials without the measurement apparatus being in contact with the samples.
2. Background of the Invention
Conventionally, mechanical properties of materials such as biological tissues or engineering materials are measured by using a testing probe to contact the samples for the measurement. In such a conventional measurement, it may be difficult to quickly image an area larger than the probe in that the probe needs to be loaded and unloaded repeatedly, which can be time-consuming.
U.S. Pat. No. 6,783,503, entitled “Method and Device for Testing the Rigidity of Biological Tissue” and assigned to Karl Storz, GmbH & Co. KG, discloses a contact-free measurement of the mechanical rigidity of a biological sample. Specifically, the sample is deformed by a jet of fluid, and the deformation is detected by optically measuring the distance between the measuring surface and the measuring device.
Disadvantages exist with the design of the '503 patent in that firstly, it failed to consider the thickness of the sample, which may affect the deformation of the sample and consequently the measurement of the mechanical rigidity of the biological sample. Furthermore, the optical distance measurement of the '503 patent merely provides limited information, i.e., the distance between the measuring surface and the measuring device, about the sample, which may not be satisfactory in a situation, where more complicated information is required.